碳氮素源對線蟲捕捉性真菌捕捉能力之影響

Effects of Carbon and Nitrogen Sources on the Trapping Ability of nematode-trapping Fungi

林玠誼(C. Y. Lin) ； 蔡東纂(T. T. Tasy)

《植物病理學會刊》 13卷4期 (2004/12) Pp. 309-316

https://doi.org/10.6649/PPB.200412_13(4).0009

摘要

自本省各地不同寄主及土壤質地作物區採集作物根圈土壤之61個樣本，利用土壤灑佈法分離不完全菌絲孢綱線蟲捕捉性真菌，測定採集土壤的pH值、有機質、土壤質地，以探討線蟲捕捉性真菌之存在與其相關性。樣本分離到線蟲捕捉性真菌的比率爲68.85%，共11種線蟲捕捉性真菌，且其中68.63%爲綱形成菌(net-forming fungi)，其中又以Monacrosporium eudermata的25.49%分離率爲最高。當土壤有機質含量高於4%時即全數分離到線蟲捕捉性真菌，土壤pH值介於2-4及5-7，分離線蟲捕捉性真菌比率爲89.47%、69.57%，較其他範圍值分離率高，但整體與線蟲捕捉性真菌的存在無明顯相關性。五種線蟲捕捉性真菌Arthrobotrys cladodes、A. musiformis、Dactylaria borchopaga、M. eudermata與M. ellipsosporium最適生長溫度爲28℃，皆可在pH值5-9下生長， 其中綱形成菌生長速度最快，以查派克培養基(Czapek's medium)作爲基礎培養基，高速碳素源深度爲1.5%、1%及3%；氮素源濃度爲0.2%、0.5%及1%，當氮素源深度爲1%時，可抑制5種線蟲捕捉性真菌生長。M. eudermata培養在0.5% maltose與0.2% NaNO3條件下對於葉芽線蟲(Aphelenchoides besseyi)具有最好的捕捉率(50%)，當碳素源提高到3%或不添加任何碳氮素源會降低捕捉線蟲能力。溫室試驗以有機添加物與豐力富高鈣即溶奶粉混合高速其碳氮比爲2.5，作爲M. eudermata養分來源，結果顯示蕹菜植株經大豆粕+奶粉+M. eudermata混合物之處理能顯著降低南方根瘤線蟲(Meloidogyne incognita)的侵入，並且促進地上部的生長，比只接種南方根瘤線蟲之蕹菜植株幹重增加90.9%。

關鍵字

線蟲捕捉性真菌 ； 南方根瘤線蟲

並列摘要

Sixty one rhizosphere soil samples from various crops in Taiwan were collected and nematode-trapping fungi were isolated by sprinkling methods. The soil pH value, soil texture, and the quantity of soil organic substrates of each soil sample were analyzed to investigate the relationships between environmental factors and the occurrence of nematode-trapping fungi. Nematode-trapping fungi were found in 68.85% of soil samples. The nematode trapping-fungi were present in soil samples containing organic substrates higher than 4%. The best growth temperature of these five nematode-trapping fungi, Arthrobotrys cladodes, A. musiformis, Dactylaria borchopaga, Monacrosporium eudermata and M. ellipsosporium were 28℃ and the optimal pH value for growth was ranged from 5 to 9. It was found that net-forming fungi grew faster than knob-forming and ring-forming fungi. Adjusted the nitrogen source in Czapek's medium to 1%, all these five nematode-trapping fungi grew slower. M. eudermata showed the best trapping ability (50%) to Aphelenchoides besseyi on the Czapek's medium with 0.5% maltose and 0.2% NaNO3. However, nematode trapping ability would be reduced when carbon source increased to 3% or when either carbon or nitrogen source were lowered under 0.2%. In the green house tests, mixtures of organic substances and milk powder were adjusted to 2.5 C/N ratio, then served as the nutrient source for M. eudermata, which was used as a biological control agent of Meloidogyne incognita. The treatment of a mixture of soybeans meal, milk powder and M. eudermata showed significant results on controlling of Meloidogyne incognita.

並列關鍵字

biological control ； Meloidogyne incognita ； nematode trapping-fungi